Of course, but that works only if the files are already in the same partition. A dmg is a virtual image, even if it's stored in the same partition, once mounted it acts like another partition.
Safari, or better, macOS and iOS include a software AV1 decoder (libdav1d), but it's used only to decode avif, and to generate file previews in Finder.
Because that's by design. The windows are meant to have different corner radius, they even explained it at WWDC. Then people forgot and rediscovered it again, like it was some new thing.
I am not saying that it's a good idea to have different corner radius, just that it's nothing new.
Every device compatible with the Matter standard[1] can be used with Apple Home (and with every other solution that supports Matter, like Google and Amazon ones), so almost everything is compatible with everything out there.
It should be based on the app size, so maybe developers will stop shipping apps with a single feature and one button that takes 700 MB because of random bloated third-party SDKs that aren't even used.